This invention relates to a motorized personal transportation vehicle, and more particularly to a two-wheeled urban transportation vehicle powered by two electric gear motors.
Four wheeled automotive passenger carrying vehicles have, of course, been provided for over one hundred years and have developed into highly efficient machines for transportation of people and goods rapidly over long and short distances. They are not, however, without their disadvantages. They are noisy, often difficult to park in congested urban areas and, being powered by internal combustion engines fuelled by gasoline or diesel oil, major sources of atmospheric pollution. There is, therefore, a need for a small light, fully enclosed, passenger vehicle, preferably but not essentially electrically powered, for use in congested urban areas to transport up to two adults and a limited amount of goods in safety in substantially all weather conditions. Numerous attempts have been made in the past to provide such vehicles, with varying degrees of success, ranging from three wheeled vehicles based on gasoline powered motorcycles to two wheeled machines, sometimes gasoline but also electrically powered, such as that shown in U.S. Pat. No. 5,366,034 issued Nov. 22, 1994 to William L. Meyers. In the Meyers vehicle a passenger compartment is pivotally suspended between two very large wheels mounted at the ends of a single axle that is perpendicular to the direction of travel. The passenger compartment is pivotally mounted beneath the axle so as to allow the compartment to rotate repeatedly in an uncontrolled and unconstrained manner about the axle upon impact of the vehicle with another object. Such a design dictates that all passengers must be securely strapped into their seats in the same manner as an airforce fighter pilot, and all goods must be secured against all movement to prevent injury or damage when the passenger compartment rotates through 360xc2x0. This design also ignores the potential reactive rotation of the passenger compartment in the everyday event of hard braking, let alone striking an immoveable object. If such rotation occurs, to the considerable discomfort of the passengers, the energy available as the compartment passes over the top and completes the circle in the down direction would increase the speed and severity of any subsequent impact. Further in the Meyers design, the attitude or pitch of the passenger compartment is controlled by wings, in the manner of a bi-plane, the upper one of which is fitted with control tabs, similar to an airplane. As the effectiveness of these wings and tabs is dependent upon the velocity of the air passing over them and the speed of the vehicle, both of which are variable, their effect and reliability are questionable.
It is, therefore, an object of the present invention to provide an electrically powered two-wheeled passenger vehicle that prevents reactive rotation of the passenger compartment due to extreme or emergency braking and in which the attitude of the passenger compartment is automatically controlled by means of powered weight transfer at the command of a balance sensing unit.
Thus, by one aspect of this invention there is provided an automotive vehicle having a pair of road wheels each rotatably mounted on a respective one of a pair of axially aligned stub axles;
a trapeze frame, comprising a pair of spaced apart side arms and a horizontal bar mounted therebetween, rotatably mounted between said road wheels and depending from said stub axles;
a weighted passenger compartment rotatably mounted on said horizontal bar and having a centre of gravity below said horizontal bar;
a pair of powered drive motors each operatively connected to a respective one of said road wheels;
means to control said motors, mounted in said passenger compartment;
braking means operatively connected to said road wheels; and
means to temporarily reduce braking force in response to angular displacement between said side arms of said trapeze frame and said passenger compartment so as to prevent rotation of said trapeze bar about said axially aligned stub axles.